Abstract: The half-measurement method is used to calculate the more complex discontinuous character which is based on limited experiments through several hypotheses and computations.The base hypothesis of the half-measurement method is that the scattering of plate with the discontinuous character is a superposition at different phases by the scattering of different components.The half-measurement method includes three hypotheses:the first hypothesis is that the scattering of plate with the discontinuous character is the scattering superposition of the plate and the discontinuous character;the second hypothesis is that the scattering of multi-discontinuous character is the summation of the scattering of all single-discontinuous character at different phases;the third hypothesis is that the scattering of discontinuous character is directly proportional to its size.This method can be used to estimate the other scattering of plate with the discontinuous character and has some advantages like high efficiency and less memory occupation.Through the research on multi-step plate and multi-gap plate,the method is proved to be valid.